Average retail gasoline prices fell 0.5 cents a gallon last week in Denver, averaging $3.58 a gallon on Sunday, three cents cheaper than the national average, according to GasBuddy.com.

The national average fell 3.7 cents a gallon last week to $3.61 a gallon.

Patrick DeHaan, senior petroleum analyst for GasBuddy.com, said there have been some large drops in oil prices and gasoline spot prices in the past two weeks.

He predicted that during the next week, the national average will fall back under $3.50 a gallon, something that hasn’t happened since April. He said further declines are possible if there is a lack of hurricanes and world tensions don’t erupt further.

However, DeHaan said there could be wide fluctuations in prices between gas stations. Motorists should shop around to find the best bargains, he said.

In Denver, prices on Sunday were 5.7 cents a gallon higher than the same day a year ago, and 12.6 cents a gallon higher than a month ago.